Liquid cooling system and personal computer using thereof

ABSTRACT

A liquid cooling system and a personal computer equipped with it, being suitable for a semiconductor device, etc, generating high heat therefrom and suppressing influences following corrosion upon an apparatus, thereby ensuring healthiness of the system as a whole, wherein it comprises: a pump for supplying cooling liquid; a heat receiving jacket being supplied with the cooling liquid, and for receiving heat generated from a heat generation body; a heat radiation pipe for radiating heat which is supplied by the cooling liquid passing through the heat receiving jacket; and a passage for circulating the cooling liquid passing through the heat radiation pipe into said pump, and the heat radiation pipe is made of material having corrosion resistance being higher than that of the heat receiving jacket.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a liquid cooling system, and inparticular, to a liquid cooling system being suitable for the structureof being ultra-small and/or thin in sizes thereof.

[0002] Semiconductor devices, being used in electronic apparatuses, suchas a computer, etc., generate heat therefrom when operating. Inparticular, high-integrated semiconductor devices in recent yearsincrease an amount of the heat generation therefrom. Since thesemiconductor devices loose the function thereof if temperature thereofexceed a certain value, cooling is necessary for such the semiconductordevices having a large amount of heat generation.

[0003] For a method for cooling the semiconductor devices of anelectronic apparatus, there are known various manners, such as ofadopting thermal conduction or air-cooling, or using a heat pipe, or bymeans of liquid cooling.

[0004] Cooling of adopting the thermal conduction is achieved byapplying materials having large thermal conductivity on a route of heatradiating, reaching from the semiconductor device to an outside of theelectronic apparatus. This method is suitable for so-called a compactelectronic apparatus, in which heat generation is relatively small, suchas a notebook-type personal computer.

[0005] With the cooling by using air, an air blower or fan is providedinside the electronic apparatus, thereby achieving the cooling of thesemiconductor device therein through compulsively circulating airthereon. This method is adopted widely for cooling of the semiconductordevices having a certain amount of heat generation, and it was alsoapplied to the personal computer by making the air blower small and thinin the sizes thereof.

[0006] Cooling with using the heat pipe, in which heat is carried out toan outside of the electronic apparatus by means of coolant enclosedwithin a pipe, was described in Japanese Patent Laying-Open No. Hei1-184699 (1989), and Japanese Patent Laying-Open No. Hei 2-244748(1989), for example. With this method, since there is provided no partof consuming electric power therein, such as the air blower or fan,therefore it has good efficiency, i.e., it increases the cooling throughthe thermal conduction further. However, with this method, there is alimit in an amount of heat that can be transferred therewith.

[0007] The cooling by means of liquid coolant is suitable for thecooling of the semiconductor device having a large amount of heatgeneration, and it was described, for example, in Japanese PatentLaying-Open No. Hei 5-1335454 (1993), Japanese Patent Laying-Open No.Hei 6-97338 (1994), Japanese Patent Laying-Open No. Hei 6-125188 (1994),and Japanese Patent Laying-Open No. Hei 10-213370 (1998), for example.However, such the cooling system of liquid is restricted in the field ofutilization thereof, such as a large-scale computer. This is, becausethe cooling system of liquid necessitates a large number of parts, suchas a pump, pipe system, heat radiation fin, etc., being exclusive usefor the cooling, the apparatus comes to be large in sizes, and it isdifficult to maintain reliability of using the liquid for coolingcomparing to other methods. It is also one of reasons, the fact that nosuch the semiconductor device requiring such the cooling by means ofliquid is used other than a field of the large-scale computer.

[0008] A technology of adopting the liquid cooling into a small-sizedapparatus, including such the notebook-sized personal computer, isdescribed in Japanese Patent Laying-Open No. Hei 6-266474 (1994). Inthis prior art, a header attached onto the semiconductor device and aheat radiation pipe separately located from it are connected with eachother by means of a flexible tube, wherein the cooling is obtained bymeans of the liquid flowing therethrough.

[0009] However, an amount increases up remarkably of heat generationfrom the semiconductor devices, which are used in the electronicdevices, such as a personal computer, a sever computer, a work station,etc., in recent years, and for the electronic apparatuses of recentyears, such as a notebook-type personal computer, it is required to beultra-small and thin in sizes thereof. For cooling of such thesemiconductor devices used in those apparatuses are applied such thecooling methods, adopting the thermal conduction, the air-cooling,and/or the heat pipe, as were mentioned previously, however the capacityof cooling is still insufficient.

[0010] Also, for applying the liquid cooling system, which wasconventionally used in a large-scaled computer into such the electronicapparatuses, being ultra-small and thin in sizes thereof, it isnecessary condition that the liquid cooling system itself is ultra-smalland thin in sizes. With this system, an amount of liquid retainedtherein is remarkably small, such as about 1/10,000. Because of thesmall amount thereof, the liquid is easily lowered or degraded inquality thereof, even with a very small amount of elusion of corrosiveion from material being in contact with the liquid, and then it promotescorrosion in the heat receiving jacket and/or the heat radiation pipe,which are made of metal. Since leakage of water stops the function ofthe apparatus, then this leakage is required be suppressed, however,measures taken on this point are insufficient, according to theconventional art.

SUMMARY OF THE INVENTION

[0011] Then, according to the present invention, an object is to providea liquid cooling system, being suitable for cooling the semiconductordevice or the like, which is used in electronic apparatuses, beingultra-small and thin in sizes, and also suppressing an influence uponthe apparatuses, accompanying with the corrosion, thereby ensuringhealthiness of the system as a whole, and further to provide a personalcomputer equipped therewith.

[0012] For dissolving such the problems as was mentioned in the above,according to the present invention, a tendency of corrosion can becontrolled, thereby providing a system obtaining protection from thecorrosion effectively, even for the computer having the structure ofbeing small and thin in sizes.

[0013] In more details, according to the present invention, there isprovided a liquid cooling system, comprising: a pump for supplyingcooling liquid; a heat receiving jacket being supplied with said coolingliquid, and for receiving heat generated from a heat generation body; aheat radiation pipe for radiating heat which is supplied by the coolingliquid passing through said heat receiving jacket; and a passage forcirculating the cooling liquid passing through said heat radiation pipeinto said pump, wherein said heat radiation pipe is made of materialhaving corrosion resistance being higher than that of said heatreceiving jacket.

[0014] Further, it may be possible to construct the heat receivingjacket be to surrounded by a waterproof sheet, thereby to improvereliability. With the corrosion resistance mentioned above, an attentionis paid to pitting corrosion with respect to ion dissolved into thecooling liquid (in particular, halogen group ions, such as fluorine,chlorine, etc., of organic matters, including rubber and plastics,dissolving from an area where it is in contact with the liquid).

[0015] For example, the heat receiving jacket is made of material,mainly containing aluminum as constituent component therein, while saidheat radiation pipe is made of stainless material. However, other thanthat, by taking the importance of thermal conductivity thereof into theconsideration, although it lowers the characteristic of corrosionresistance from that mentioned above, it may be possible, for example,to make the heat receiving jacket of material, mainly containing copperas constituent component therein, while the heat radiation pipe ofstainless material. Other than those, though there may be a possibilityof lowering the characteristic of corrosion resistance, there is alsopossible that the heat receiving jacket is made of material, mainlycontaining aluminum as constituent component therein, however the heatradiation pipe of material, mainly containing copper as constituentcomponent therein, from the same viewpoint to the above. However, inthis case, it is preferable to take countermeasure, such as, of addingof an anticorrosive agent and/or corrosion inhibiter agent into copper,from a viewpoint of the corrosion resistance thereof.

[0016] Also, according to the present invention, the heat radiation pipeis made of material having corrosion resistance being higher than thatof the heat receiving jacket; and thickness from the cooling liquidpassage up to surface of said jacket in the heat receiving jacket isthicker than the thickness from the cooling liquid passage up to surfaceof the heat radiation pipe in the heat radiation pipe.

[0017] Alternatively, it can be also considered that the heat receivingjacket is made of material, mainly containing copper as constituentcomponent therein, and also the heat radiation pipe of material, mainlycontaining copper as constituent component therein. However, in thiscase, it is preferable to put into the corrosion inhibiter agent for thematerial of copper group, in addition thereto, from a viewpoint ofincreasing the effect of inhibiting corrosion.

[0018] Alternatively, it can be also considered that the heat receivingjacket is made of material, mainly containing aluminum as constituentcomponent therein, and also the heat radiation pipe of material, mainlycontaining aluminum as constituent component therein. However, in thiscase, it is preferable to put into the corrosion inhibiter agent for thematerial of aluminum group, in addition thereto, from a viewpoint ofincreasing the effect of inhibiting corrosion.

[0019] And, it is preferable to provide a personal computer, comprisinga semiconductor element, a signal input portion and a display device,and further including a heat receiving jacket being supplied with saidcooling liquid, and for receiving heat generated from a heat generationbody; a heat radiation pipe for radiating heat which is supplied by thecooling liquid passing through said heat receiving jacket; and a passagefor circulating the cooling liquid passing through said heat radiationpipe into said pump, in addition to those features mentioned above.

[0020] As an example of a notebook-type personal computer, in moredetails thereof, there is provided a personal computer, comprising: amain body including a semiconductor element and a signal input portion;a display device having a display portion, being connected with saidmain body through a movable mechanism; a pump for emitting coolingliquid; a heat receiving jacket being disposed within said main body andsupplied with said cooling liquid, and for receiving heat generatedwithin said semiconductor element; a heat radiation pipe being disposedin a back surface of said display portion of said display device, andfor radiating heat which is supplied by the cooling liquid passingthrough said heat receiving jacket; and a passage for circulating thecooling liquid passing through said heat radiation pipe into said pump,wherein: said heat receiving jacket is made of material, mainlycontaining copper as constituent component therein, and also said heatradiation pipe is made of material, mainly containing copper asconstituent component therein; and thickness from said cooling liquidpassage up to surface of said jacket in said heat receiving jacket isthicker than the thickness from said cooling liquid passage up tosurface of said heat radiation pipe in said heat radiation pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those and other features, objects and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings wherein:

[0022]FIG. 1 shows a perspective view of an embodiment of the presentinvention;

[0023]FIG. 2 shows a block diagram of the embodiment of the presentinvention;

[0024]FIG. 3 shows a block diagram of other embodiment of the presentinvention; and

[0025]FIG. 4 shows a block diagram of further other embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments according to the present invention willbe fully explained by referring to the attached drawings.

[0027]FIG. 1 shows a notebook-type personal computer using the liquidcooling system according to the present invention. To a semiconductorelement or device 5 mounted within a main housing or chassis 6 isconnected a heat receiving jacket 2, in which a flow passage isprovided. In the main housing 6 is also provided a pump 1. Behind adisplay panel of a display device case or housing 7 is provided a heatradiation pipe 4. The pump 1, the heat receiving jacket 2 and the heatradiation pipe 4 are connected with a connector pipe 3 in a closedloop-like manner, as shown in the figure, and in an inside of them iscirculated cooling liquid. As the cooling liquid mentioned above may beused a coolant, including such as, a group of pure water. Basically,water can be used therein. Depending upon the cases, it can beconsidered to add corrosion inhibiter agent in it, etc.

[0028] Though depending upon the size of the apparatus to be applied,the amount of cooling liquid can be considered to be, for example, aboutfrom 5 cc to 10 cc in a case of the notebook-type personal computer, andabout from 5 cc to 200 cc in a case of the desktop-type personalcomputer.

[0029]FIG. 2 shows the first embodiment of the liquid cooling system ofthe notebook-type personal computer shown in the FIG. 1,diagrammatically. The heat radiation pipe 4 is made of material, beingsuperior in corrosion resistance property than that of the heatreceiving jacket 2. In the present embodiment, the heat receiving jacket2 is shown in the condition of being enclosed by a waterproof sheet 8.

[0030] With this, the heat receiving jacket 2 is increased in an amountof corrosion, to be higher than that in the heat radiation pipe 4,thereby letting ions dissolved or melted into the cooling liquid fromthe material of rubber or plastic, etc., which is in contact therewith,so as to suppress corrosion of the heat radiation pipe 4. Since liquidleakage or the like due to pitting corrosion can be suppressed in theheat radiation pipe 4 having a large area, it is sufficient to provideor take measures against only the corrosion in the heat receiving jacket2 having a small area, therefore it is possible to obtain an effectagainst the corrosion of the system as a whole, with high efficiency.

[0031] Also, enclosing or covering the heat receiving jacket 2 by thewaterproof sheet 8 further enables or enhances the prevention of leakageof water even when the corrosion pitting corrosion is formed through thematerial due to promotion of corrosion in the heat receiving jacket.

[0032] Herein, description will be given on a case where the material ofthe heat receiving jacket 2 is aluminum (a jacket cast with ADC material(for example, ADC12)) and the heat radiation pipe is a stainless pipe(using SUS304). Aluminum is suitable as the material of the heatreceiving jacket from a viewpoint of thermal conductivity, workabilityin machining, and also light weight character thereof. Aluminum formsoxidization film of Al₂O₃ on the surface thereof in an atmosphere ofneutral region in pH, thereby obtaining the property of corrosionresistance. On a while, stainless steel shows superior property ofcorrosion resistance in fresh water through passivity film thereon. Anamount of elution of Fe ion is small. Although co-existence of differentkinds of metals is not preferable from a viewpoint of corrosion, in manycases, however, the influence by the ion liquefying from aluminum can besuppressed by the film on the surface film of stainless. In additionthereto, as was mentioned previously, corrosion in the heat radiationpipe 4 can be suppressed through the function of such the ion asmentioned above, by producing reaction of ions, such as, a chloride orothers dissolved from rubber and/or plastic which are in contact withthe cooling liquid, upon the heat receiving jacket 2.

[0033] Also, the thickness, from a liquid portion of the heat receivingjacket 2 up to the surface thereof, is thicker than the heat radiationpipe 4, and this enables the heat receiving jacket 4 to perform thermaldiffusion from a high-heat generation body, such as, the semiconductorelement or the like, with high efficiency, as well as, suppress thepitting corrosion portion from reaching to the surface even when itoccurs.

[0034] Other than this, in a case where the heat receiving jacket 2 ismade of copper while the heat radiation pipe 4 of stainless, such thestructure also can be applied if considering importance of the thermalconductivity of the heat generation body, such as, the semiconductorelement, etc. If the material is copper, though showing superiorcharacter of corrosion resistance in fresh water, through theoxidization coating film formed on the surface thereof, in the samemanner as stainless steal, however it liquefied out an amount of Cu ionmuch larger than the stainless steel. Then, it is preferable to providethe structure of prohibiting the leakage of water by means of thewaterproof sheet, when the corrosion proceeds on aluminum through Cuion. And, it is also effective to add corrosion inhibiter (for example,benzotriazol, mercapobenzothiazol, tolyltriazol, etc.) for use ofmaterial of copper group, into the coolant in advance, thereby tosuppress the elution of Cu ion.

[0035] Also, other than those, it can be considered to use a heatradiation pipe made of copper, while using the heat receiving jacket ofaluminum. However, in this case, it is preferable to take measures, suchas, adding corrosion protection agent for copper, from a viewpoint ofthe property on corrosion resistance thereof.

[0036]FIG. 3 shows another example of the cooling system for thenotebook-type personal computer shown in the FIG. 1, diagrammatically.As shown in the FIG. 3, it is possible to construct it, so that itcomprises a thermal conductive sheet 9 of waterproof character betweenthe heat receiving jacket 2 and the semiconductor element 5.

[0037] For example, the heat receiving jacket may be made to be thickerin the thickness other than the surface of the thermal conductive sheet,so as to inhibit the leakage of water therein.

[0038] Further, with an apparatus to be applied with it into, it iseffective to apply it, in particular, into the liquid cooling system fora semiconductor device, generating an amount of heat more than 30 W.

[0039] Other examples will be shown hereinafter. In any one of them, themeasures are eased or simplified by identifying the portion wherecorrosion is much, thereby to improve reliability as a whole. FIG. 4shows an example of them, diagrammatically. The heat receiving jacket 2is made of material being superior in the character of corrosionresistance to that of the heat radiation pipe 4. In the present figure,the heat radiation pipe 4 is enclosed or covered with by the waterproofsheet 8, thereround.

[0040] In this embodiment, attention to be paid with the measuresagainst the corrosion can be focused onto the heat radiation pipe 4.With this, the leakage of water can be protected by enclosing or coatedwith the heat radiation pipe with the waterproof sheet 8, even if thepitting is formed due to the promotion of corrosion penetrating throughthe material of the heat radiation pipe 4.

[0041] Herein, description will be given on a case where the material ofthe heat radiation pipe is aluminum, while that of the water receivingjacket is stainless steel. This is a result of taking into considerationthe fact that it is easier to take the measures against corrosion in acase of the heat radiation pipe 4, depending on the relationship betweendisposition of the heat radiation pipe 4 and the heat receiving jacket2. Much of ion coming from the rubber, etc., in the system reacts in theheat radiation pipe 4, therefore it can be considered that the corrosionis suppressed in the heat receiving jacket 2.

[0042] Also, in a case where the material of the heat radiation pipe isstainless steel while the heat receiving jacket of copper, in the placethereof, it is preferable to take a means of covering or coating withthe waterproof sheet, etc., together with.

[0043] As other embodiment, it can be considered that the heat receivingjacket and the heat radiation jacket are made of the same kind ofmaterial. In that instance, it is preferable to enclose or cover amember being thicker in the thickness with the waterproof sheet 8.

[0044] In a case where the heat receiving jacket 2 is disposed in themain housing 6 while the heat radiation pipe in the display devicehousing 7, it is preferable that an allowable size for the heatradiation pipe 4 is smaller comparing to that for the heat receivingjacket 2. Also, in order to conduct heat of the heat generation body tothe heat receiving jacket 2 effectively, since there is needed a certainthickness for diffusing heat therein, it is preferable that thethickness of the heat radiation pipe 4 is thinner comparing to that ofthe heat receiving jacket 2.

[0045] Corrosion proceeds on both the heat receiving jacket 2 and theheat radiation pipe 4. However, it is possible to suppress that metalion flowing out from one of them gives influences upon corrosion of theother, comparing to the case of combining different kinds of metalstherein.

[0046] For example, it is possible to consider that both the heatreceiving jacket 2 and the heat radiation pipe 4 are made of copper. Itcan occurs that bacteria is mixed into a water when it is used as thecooling liquid, for example, in the manufacturing processes thereof.Even in such the case, the structure, having an area where the coolingliquid is in contact with the copper as much, can suppress the corrosionaccompanying with the bacteria at the portion being in contact with thecooling liquid, thereby improving reliability of the system as a whole.

[0047] Also, other than those, it can be considered that the heatreceiving jacket and the heat radiation pipe are made of the same kingof material. In this case, since the sizes and weight thereof can bemade as small and light as possible, it is preferable to be applied intothe personal computer of small size and lightweight. In that instance,it is preferable to enclose or cover the member being thinner in thethickness with the waterproof sheet 8.

[0048] In a case where the heat radiation pipe 4 and the heat receivingjacket 2 are made of copper and aluminum, respectively, it is possibleto suppress an amount of corrosion if adding the corrosion inhibiteragents for copper and aluminum into the coolant in advance.

[0049] As was fully explained in the above, according to the presentinvention, it is possible to provide a liquid cooling system, beingsuitable for high heat generation body, such as the semiconductordevice, etc., and suppressing ill influences following with thecorrosion on an apparatus, thereby ensuring healthiness of the system asa whole, and a personal computer equipped with such the structure.

[0050] While we have shown and described several embodiments inaccordance with our invention, it should be understood that thedisclosed embodiments are susceptible of changes and modificationswithout departing from the scope of the invention. Therefore, we do notintend to be bound by the details shown and described herein but intendto cover all such changes and modifications falling within the ambit ofthe appended claims.

What is claimed is:
 1. A liquid cooling system, comprising: a pump forsupplying cooling liquid; a heat receiving jacket being supplied withsaid cooling liquid, and for receiving heat generated from a heatgeneration body; a heat radiation pipe for radiating heat which issupplied by the cooling liquid passing through said heat receivingjacket; and a passage for circulating the cooling liquid passing throughsaid heat radiation pipe into said pump, wherein said heat radiationpipe is made of material having corrosion resistance being higher thanthat of said heat receiving jacket.
 2. A liquid cooling system, asdefined in the claim 1, wherein said heat receiving jacket is made ofmaterial, mainly containing aluminum as constituent component therein,while said heat radiation pipe is made of stainless material.
 3. Aliquid cooling system, comprising: a pump for supplying cooling liquid;a heat receiving jacket being supplied with said cooling liquid, and forreceiving heat generated from a heat generation body; a heat radiationpipe for radiating heat which is supplied by the cooling liquid passingthrough said heat receiving jacket; and a passage for circulating thecooling liquid passing through said heat radiation pipe into said pump,wherein: said heat radiation pipe is made of material having corrosionresistance being higher than that of said heat receiving jacket; andthickness from said cooling liquid passage up to surface of said jacketin said heat receiving jacket is thicker than the thickness from saidcooling liquid passage up to surface of said heat radiation pipe in saidheat radiation pipe.
 4. A liquid cooling system, comprising: a pump forsupplying cooling liquid; a heat receiving jacket being supplied withsaid cooling liquid, and for receiving heat generated from a heatgeneration body; a heat radiation pipe for radiating heat which issupplied by the cooling liquid passing through said heat receivingjacket; and a passage for circulating the cooling liquid passing throughsaid heat radiation pipe into said pump, wherein: said heat receivingjacket is made of material, mainly containing copper as constituentcomponent therein, and also said heat radiation pipe is made ofmaterial, mainly containing copper as constituent component therein. 5.A liquid cooling system, comprising: a pump for supplying coolingliquid; a heat receiving jacket being supplied with said cooling liquid,and for receiving heat generated from a heat generation body; a heatradiation pipe for radiating heat which is supplied by the coolingliquid passing through said heat receiving jacket; and a passage forcirculating the cooling liquid passing through said heat radiation pipeinto said pump, wherein: said heat receiving jacket is made of material,mainly containing aluminum as constituent component therein, while saidheat radiation pipe is made of material, mainly containing aluminum asconstituent component therein.
 6. A personal computer, comprising: asemiconductor element; a signal input portion; and a display device, andfurther including: a pump for supplying cooling liquid; a heat receivingjacket being supplied with said cooling liquid, and for receiving heatgenerated from a heat generation body; a heat radiation pipe forradiating heat which is supplied by the cooling liquid passing throughsaid heat receiving jacket; and a passage for circulating the coolingliquid passing through said heat radiation pipe into said pump, wherein:said heat radiation pipe is made of material having corrosion resistancebeing higher than that of said heat receiving jacket.
 7. A liquidcooling system, as defined in the claim 6, wherein said heat receivingjacket is made of material, mainly containing aluminum as constituentcomponent therein, while said heat radiation pipe is made of stainlessmaterial.
 8. A personal computer, comprising: a semiconductor element; asignal input portion; and a display device, and further including: apump for supplying cooling liquid; a heat receiving jacket beingsupplied with said cooling liquid, and for receiving heat generated froma heat generation body; a heat radiation pipe for radiating heat whichis supplied by the cooling liquid passing through said heat receivingjacket; and a passage for circulating the cooling liquid passing throughsaid heat radiation pipe into said pump, wherein: said heat receivingjacket is made of material, mainly containing copper as constituentcomponent therein, and also said heat radiation pipe is made ofmaterial, mainly containing copper as constituent component therein. 9.A personal computer, comprising: a semiconductor element; a signal inputportion; and a display device, and further including: a pump forsupplying cooling liquid; a heat receiving jacket being supplied withsaid cooling liquid, and for receiving heat generated from a heatgeneration body; a heat radiation pipe for radiating heat which issupplied by the cooling liquid passing through said heat receivingjacket; and a passage for circulating the cooling liquid passing throughsaid heat radiation pipe into said pump, wherein: said heat receivingjacket is made of material, mainly containing aluminum as constituentcomponent therein, and also said heat radiation pipe is made ofmaterial, mainly containing aluminum as constituent component therein.10. A personal computer, comprising: a semiconductor element; a signalinput portion; and a display device, and further including: a pump forsupplying cooling liquid; a heat receiving jacket being supplied withsaid cooling liquid, and for receiving heat generated from a heatgeneration body; a heat radiation pipe for radiating heat which issupplied by the cooling liquid passing through said heat receivingjacket; and a passage for circulating the cooling liquid passing throughsaid heat radiation pipe into said pump, wherein: said heat receivingjacket is made of material, mainly containing copper as constituentcomponent therein, and also said heat radiation pipe is made ofmaterial, mainly containing copper as constituent component therein. 11.A personal computer, comprising: a main body including a semiconductorelement and a signal input portion; a display device having a displayportion, being connected with said main body through a movablemechanism; a pump for emitting cooling liquid; a heat receiving jacketbeing disposed within said main body and supplied with said coolingliquid, and for receiving heat generated within said semiconductorelement; a heat radiation pipe being disposed in a back surface of saiddisplay portion of said display device, and for radiating heat which issupplied by the cooling liquid passing through said heat receivingjacket; and a passage for circulating the cooling liquid passing throughsaid heat radiation pipe into said pump, wherein: said heat receivingjacket is made of material, mainly containing copper as constituentcomponent therein, and also said heat radiation pipe is made ofmaterial, mainly containing copper as constituent component therein; andthickness from said cooling liquid passage up to surface of said jacketin said heat receiving jacket is thicker than the thickness from saidcooling liquid passage up to surface of said heat radiation pipe in saidheat radiation pipe.